1. Field of the Invention
The present invention relates to a thin-film magnetic head having at least a magnetoresistive element for reading and a method of manufacturing such a magnetic head, and to a thin-film magnetic head material used for producing a composite thin-film magnetic head having a magnetoresistive element and an induction-type magnetic transducer and a method of manufacturing such a thin-film magnetic head material.
2. Description of the Related Art
Performance improvements in thin-film magnetic heads have been sought with an increase in surface recording density of a hard disk drive. A composite thin-film magnetic head has been widely used which is made of a layered structure including a recording head having an induction magnetic transducer for writing and a reproducing head having a magnetoresistive (MR) element for reading. MR elements include an anisotropic magnetoresistive (AMR) element that utilizes the AMR effect and a giant magnetoresistive (GMR) element that utilizes the GMR effect. A reproducing head using an AMR element is called AMR head or simply MR head. A reproducing head using a GMR element is called GMR head. An AMR head is used as a reproducing head whose surface recording density is more than 1 gigabit per square inch. A GMR head is used as a reproducing head whose surface recording density is more than 3 gigabits per square inch.
An AMR head comprises an AMR film having the AMR effect. In place of the AMR film a GMR head comprises a GMR film having the GMR effect. The configuration of the GMR head is similar to that of the AMR head. However, the GMR film exhibits a greater change in resistance under a specific external magnetic field compared to the AMR film. As a result, the reproducing output of the GMR head is about three to five times as great as that of the AMR head.
The MR film may be changed in order to improve the performance of a reproducing head. In general, an AMR film is made of a magnetic substance that exhibits the MR effect and has a single-layer structure. In contrast, many of GMR films have a multilayer structure consisting of a plurality of films. There are several types of mechanisms of producing the GMR effect. The layer structure of a GMR film depends on the mechanism. GMR films include a superlattice GMR film, a granular film, a spin valve film and so on. The spin valve film is most efficient since the film has a relatively simple structure, exhibits a great change in resistance in a low magnetic field, and suitable for mass production. The performance of the reproducing head is thus easily improved by replacing the AMR film with a GMR film and the like with an excellent magnetoresistive sensitivity.
Besides selection of a material as described above, the pattern width such as the MR height, in particular, determines the performance of a reproducing head. The MR height is the length (height) between the end of the MR element closer to the air bearing surface (medium facing surface) and the other end. The MR height is basically controlled by an amount of lapping when the air bearing surface is processed.
Many of reproducing heads have a structure in which the MR element is electrically and magnetically shielded by a magnetic material.
Referring to FIG. 91 to FIG. 100, an example of a manufacturing method of a composite thin-film magnetic head will now be described as an example of a manufacturing method of a related-art thin-film magnetic head. FIG. 91A to FIG. 98A are cross sections orthogonal to the air bearing surface. FIG. 91B to FIG. 98B are cross sections parallel to the air bearing surface of the pole portion.
According to the manufacturing method, as shown in FIGS. 91A and 91B, an insulating layer 1102 made of alumina (Al2O3), for example, of about 5 to 10 xcexcm in thickness is deposited on a substrate 1101 made of aluminum oxide and titanium carbide (Al2O3xe2x80x94TiC), for example. On the insulating layer 1102 a bottom shield layer 1103 made of a magnetic material of 2 to 3 xcexcm in thickness is formed for a reproducing head.
Next, as shown in FIGS. 92A and 92B, on the bottom shield layer 1103 alumina or aluminum nitride, for example, of 50 to 100 nm in thickness is deposited through sputtering to form a bottom shield gap film 1104 as an insulating layer. On the bottom shield gap film 1104 an MR film of tens of nanometers in thickness is formed for making an MR element 1105 for reproduction. Next, on the MR film a photoresist pattern 1106 is selectively formed where the MR element 1105 is to be formed. The photoresist pattern 1106 takes a shape that easily allows lift-off, such as a shape having a T-shaped cross section. Next, with the photoresist pattern 1106 as a mask, the MR film is etched through ion milling to form the MR element 1105. The MR element 1105 may be either a GMR element or an AMR element.
Next, as shown in FIGS. 93A and 93B, on the bottom shield gap film 1104 a pair of first conductive layers 1107 whose thickness is tens of nanometers are formed, using the photoresist pattern 1106 as a mask. The first conductive layers 1107 are electrically connected to the MR element 1105. The first conductive layers 1107 may have a multilayer structure including TiW, CoPt, TiW, and Ta, for example. Next, as shown in FIGS. 94A and 94B, the photoresist pattern 1106 is lifted off. Although not shown in FIGS. 94A and 94B, a pair of second conductive layers whose thickness is 50 to 100 nm are formed in a specific pattern. The second conductive layers are electrically connected to the first conductive layers 1107. The second conductive layers may be made of copper (Cu), for example. The first conductive layers 1107 and the second conductive layers make up leads electrically connected to the MR element 1105.
Next, as shown in FIG. 95A and FIG. 95B, a top shield gap film 1108 of 50 to 150 nm in thickness is formed as an insulating layer on the bottom shield gap film 1104 and the MR film 1105. The MR film 1105 is embedded in the shield gap films 1104 and 1108. Next, on the top shield gap film 1108 a top shield layer-cum-bottom magnetic layer (called top shield layer in the following description) 1109 of about 3 xcexcm in thickness is formed. The top shield layer 1109 is made of a magnetic material and used for both a reproducing head and a recording head.
Next, as shown in FIG. 96A and FIG. 96B, on the top shield layer 1109, a recording gap layer 1110 made of an insulating film such as an alumina film is formed whose thickness is about 0.2 to 0.3 xcexcm. On the recording gap layer 1110 a photoresist layer 1111 for determining the throat height is formed into a specific pattern whose thickness is about 1.0 to 2.0 xcexcm. Next, on the photoresist layer 1111 a thin-film coil 1112 of a first layer is made for the induction-type recording head. The thickness of the thin-film coil 1112 is 3 xcexcm. Next, a photoresist layer 1113 is formed into a specific pattern on the photoresist layer 1111 and the coil 1112. On the photoresist layer 1113 a thin-film coil 1114 of a second layer is then formed into a thickness of 3 xcexcm.
Next, a photoresist layer 1115 is formed into a specific pattern on the photoresist layer 1113 and the coil 1114.
Next, as shown in FIG. 97A and FIG. 97B, the recording gap layer 1110 is partially etched in a portion behind the coils 1112 and 1114 (the right side of FIG. 97A) to form a magnetic path. A top pole layer 1116 of about 3 xcexcm in thickness is then formed on the recording gap layer 1110 and the photoresist layers 1111, 1113 and 1115. The top pole layer 1116 is made of a magnetic material for the recording head such as Permalloy (NiFe) or FeN as a high saturation flux density material. The top pole layer 1116 comes to contact with the top shield layer (bottom pole layer) 1109 and is magnetically coupled to the top shield layer 1109 in a portion behind the coils 1112 and 1114.
As shown in FIG. 98A and FIG. 98B, the recording gap layer 1110 and the top shield layer (bottom pole layer) 1109 are etched through ion milling, using the top pole layer 1116 as a mask. Next, an overcoat layer 1117 of alumina, for example, having a thickness of 20 to 30 xcexcm is formed to cover the top pole layer 1116. Finally, machine processing of the slider is performed to form the air bearing surface of the recording head and the reproducing head. The thin-film magnetic head is thus completed. As shown in FIG. 98B, the structure is called trim structure wherein the sidewalls of the top pole layer 1116, the recording gap layer 1110, and part of the top shield layer (bottom pole layer) 1109 are formed vertically in a self-aligned manner. The trim structure suppresses an increase in the effective track width due to expansion of the magnetic flux generated during writing in a narrow track.
FIG. 99 is a top view of the thin-film magnetic head manufactured as described above. The overcoat layer 1117 is omitted in FIG. 99. FIG. 100 is a top view wherein the MR element 1105, the first conductive layer 1107 and the second conductive layer 1118 are formed on the bottom shield gap film 1104. FIG. 91A to FIG. 98A are cross sections taken along line 98Axe2x80x9498A of FIG. 99. FIG. 91B to FIG. 98B are cross sections taken along line 98Bxe2x80x9498B of FIG. 99.
As shown in FIG. 99 and FIG. 100, the related-art thin-film magnetic head has the structure wherein the conductive layers 1107 and 1118 connected to the MR element 1105 are inserted in a wide region between the bottom shield layer 1103 and the top shield layer 1109 for shielding the MR element 1105. The very thin bottom shield gap film 1104 and top shield gap film 1108 are each placed between the shield layer 1103 and the conductive layers 1107 and 1118 and between the shield layer 1109 and the conductive layers 1107 and 1118, respectively. High insulation property is therefore required for the shield gap films 1104 and 1108. The yields of the thin-film magnetic heads thus greatly depend on the insulation property.
With improvements in performance of the recording head, a problem of thermal asperity comes up. Thermal asperity is a reduction in reproducing characteristic due to self-heating of the reproducing head during reproduction. To overcome thermal asperity, a material with high cooling efficiency is required for the bottom shield layer 1103 and the shield gap films 1104 and 1108 in the related-art. Therefore, the bottom shield layer 1103 is made of a magnetic material such as Permalloy or Sendust in the related-art. The shield gap films 1104 and 1108 are made of a material such as alumina, through sputtering, into a thickness of 100 to 150 nm, for example. The shield gap films 1104 and 1108 thus magnetically and electrically isolate the shield layers 1103 and 1109 from the MR element 1105 and the conductive layers 1107 and 1118.
It is inevitable that thermal asperity should be overcome in order to improve the performance of the reproducing head. Recently, the thickness of the shield gap films 1104 and 1108 has been reduced to as thin as 50 to 100 nm, for example. The cooling efficiency of the MR element 1105 is thereby improved so as to overcome thermal asperity.
However, since the shield gap films 1104 and 1108 are formed through sputtering, faults may result in the magnetic and electrical insulation that isolates the shield layers 1103 and 1109 from the MR element 1105 and the conductive layers 1107 and 1118, due to particles or pinholes in the films. Such faults more often result if the shield gap films 1104 and 1108 are thinner.
In order to improve the output characteristic of the reproducing head, it is preferred that the wiring resistance of the conductive layer connected to the MR element is as low as possible so that a minute change in the output signal corresponding to a minute change in resistance of the MR element can be detected. Therefore, the area of the conductive layer 1118 is often designed to be large in the related-art. However, the areas of the portions of the conductive layers 1118 that face the shield gap films 1104 and 1108 are made large, as a result. If the shield gap films 1104 and 1108 are thin as described above, magnetic and electrical insulation faults may more often result between the conductive layers 1118 and each of the shield layers 1103 and 1109.
As described above, it is preferred that the wiring resistance of the conductive layers connected to the MR element is low to improve the output characteristic of the reproducing head. However, there is a limit to reducing the wiring resistance of the conductive layers since the conductive layers 1107 and 1118 as thin as 50 to 100 nm are inserted between the shield layers 1103 and 1109 in the related-art thin-film magnetic head.
Since a narrow track width is required for the thin-magnetic head, a minute-size MR element is required. For the GMR head, in particular, it is required to precisely detect the output signal of the minute MR element. It is therefore required to reduce noises caused by internal factors such as the coils of the induction-type recording head or external factors such as the motor of the hard disk drive. However, the conductive layers 1118 carry noises in the related-art thin-film magnetic head. Such noises may reduce the performance of the reproducing head.
In Japanese Patent Application Laid-open Hei 9-312006 (1997) a technique is disclosed for reducing the electric resistance of the lead and preventing insulation faults between the lead and the top shield. The length of the bottom shield is made shorter than the top shield in the direction of drawing out the lead connected to the MR element from between the top and bottom shields. The thickness of the portion of the lead between the top and bottom shields is made thin. The portion of the lead off the bottom shield is made thick and to protrude downward.
In the technique, however, the lead is hardly shielded by the bottom shield. As a result, magnetic flux from the coil is easily received in the GMR head that requires a high output. The lead therefore tends to carry noises.
A technique disclosed in Japanese Patent Application Laid-open Sho 60-93613 (1985) is that a spacer layer is formed on an MR element and contact holes are made in the spacer layer to expose part of the MR element. A shield film and a conductive film (lead) are then formed at the same time, and the conductive film is connected to the MR element through the contact holes.
The technique prevents insulation faults between the conductive film and the shield film. However, the conductive film tends to carry noises since the conductive film is not shielded by the shield film.
It is a first object of the invention to provide a thin-film magnetic head and a method of manufacturing the same and a thin-film magnetic head material and a method of manufacturing the same for improving the insulation property between the shield layer and the conductive layer connected to the magnetoresistive element without increasing the thickness of the insulating layer between the shield layer and the magnetoresistive element.
It is a second object of the invention to provide a thin-film magnetic head and a method of manufacturing the same and a thin-film magnetic head material and a method of manufacturing the same for reducing the wiring resistance of the conductive layer connected to the magnetoresistive element.
It is a third object of the invention to provide a thin-film magnetic head and a method of manufacturing the same and a thin-film magnetic head material and a method of manufacturing the same for reducing the effect of noises on the conductive layer connected to the magnetoresistive element.
A first thin-film magnetic head of the invention comprises: a magnetoresistive element; a first shield layer and a second shield layer for shielding the magnetoresistive element, wherein portions of the first shield layer and the second shield layer facing a recording medium are opposed to each other with the magnetoresistive element; a first insulating layer provided between the magnetoresistive element and the first shield layer and a second insulating layer provided between the magnetoresistive element and the second shield layer; a conductive layer connected to the magnetoresistive element; and a groove in which at least part of the conductive layer is placed, the groove being formed in either the first shield layer or the second shield layer, or between the first and second shield layers. The at least part of the conductive layer is placed in the groove, being insulated from the shield layer having the groove or the shield layers facing the groove.
In the first thin-film magnetic head of the invention, the at least part of the conductive layer connected to the magnetoresistive element is placed in the groove formed in either the first shield layer or the second shield layer, or between the first and second shield layers, being insulated from the shield layer having the groove or the shield layers facing the groove. As a result, the insulation property is improved between the conductive layer and the shield layer without increasing the thickness of the insulating layer between the magnetoresistive element and the shield layer.
In the first thin-film magnetic head of the invention, the groove may be formed in the first shield layer. In this case the following configurations (1) to (3) are possible. (1) The at least part of the conductive layer placed in the groove is made of a material the same as a material the first shield layer is made of. (2) The thin-film magnetic head further comprises a seed layer electrically connected to the first shield layer, formed in a region greater than a region where the first shield layer is formed, and used for forming the first shield layer. (3) The first shield layer is divided into a portion facing the magnetoresistive element and a portion not facing the magnetoresistive element.
The first thin-film magnetic head of the invention may further comprise an insulating film placed in the groove. The insulating film insulates the at least part of the conductive layer from the shield layer having the groove or the shield layers facing the groove.
The first thin-film magnetic head of the invention may further comprise an induction-type magnetic transducer having two magnetic layers magnetically coupled to each other and a thin-film coil placed between the two magnetic layers. Parts of sides of the two magnetic layers facing a recording medium include magnetic pole portions opposed to each other with a gap layer in between. The magnetic layers are each made up of at least one layer. In this case the following configurations (1) to (3) are possible. (1) One of the first and second shield layers functions as one of the two magnetic layers as well. (2) At least part of the groove is placed around a region facing the two magnetic layers and the thin-film coil of the induction-type magnetic transducer. (3) At least part of the groove is placed to pass through a region facing the two magnetic layers and the thin-film coil of the induction-type magnetic transducer.
The first thin-film magnetic head of the invention may further comprise a shield layer for shielding the at least part of the conductive layer.
In the first thin-film magnetic head of the invention, the second shield layer may include a first portion at least part of which is placed in the same plane as the first shield layer and a second portion connected to the first portion, the second portion being opposed to the first shield layer with the magnetoresistive element in between. The groove is formed between the first shield layer and the first portion of the second shield layer.
With the above configuration the thin-film magnetic head may further comprise an induction-type magnetic transducer having two magnetic layers magnetically coupled to each other and a thin-film coil placed between the two magnetic layers. Parts of sides of the two magnetic layers facing a recording medium include magnetic pole portions opposed to each other with a gap layer in between. The magnetic layers are each made up of at least one layer. In this case the following configurations (1) and (2) are possible. (1) At least part of the thin-film coil is placed on a side of the second portion of the second shield layer in a direction parallel to surfaces of the second portion. (2) The thin-film magnetic head further comprises a base body having a concave potion. At least part of the first shield layer is placed in a portion other than the concave portion on the surface of the base body where the concave portion is formed. Part of the first portion of the second shield layer is placed in a portion other than the concave portion on the surface of the base body where the concave portion is formed. The remaining part of the first portion of the second shield layer is placed along the inner surface of the concave portion. At least part of the thin-film coil is placed in the concave portion.
A second or third thin-film magnetic head of the invention comprises: a magnetoresistive element; a first shield layer and a second shield layer for shielding the magnetoresistive element, wherein portions of the first shield layer and the second shield layer facing a recording medium are opposed to each other with the magnetoresistive element in between; a first insulating layer provided between the magnetoresistive element and the first shield layer and a second insulating layer provided between the magnetoresistive element and the second shield layer; and a conductive layer connected to the magnetoresistive element. The first shield layer and at least part of the conductive layer are made of one material, placed in one plane and insulated from each other.
The second thin-film magnetic head of the invention further comprises a shield layer for shielding the at least part of the conductive layer.
The third thin-film magnetic head of the invention further comprises a seed layer electrically connected to the at least part of the conductive layer, formed in a region greater than a region where the at least part of the conductive layer is formed, and used for forming the at least part of the conductive layer.
In the second or third thin-film magnetic head of the invention, the first shield layer and at least part of the conductive layer are made of one material, placed in one plane and insulated from each other. As a result, the insulation property is improved between the conductive layer and the shield layer without increasing the thickness of the insulating layer between the magnetoresistive element and the shield layer.
The third thin-film magnetic head of the invention may further comprise a shield layer for shielding the at least part of the conductive layer.
A first method of the invention is provided for manufacturing a thin-film magnetic head comprising: a magnetoresistive element; a first shield layer and a second shield layer for shielding the magnetoresistive element, wherein portions of the first shield layer and the second shield layer facing a recording medium are opposed to each other with the magnetoresistive element in between; a first insulating layer provided between the magnetoresistive element and the first shield layer and a second insulating layer provided between the magnetoresistive element and the second shield layer; and a conductive layer connected to the magnetoresistive element.
The first method of manufacturing a thin-film magnetic head of the invention includes the steps of: forming the first shield layer; forming the first insulating film on the first shield layer; forming the magnetoresistive element on the first insulating layer; forming the second insulating layer on the magnetoresistive element and the first insulating layer; and forming the second shield layer so that the portion of the second shield layer facing the recording medium is opposed to the first shield layer with the first insulating layer, the magnetoresistive element and the second insulating layer in between. A groove in which at least part of the conductive layer is placed is formed in either the first shield layer or the second shield layer, or between the first and second shield layers in at least one of the step of forming the first shield layer and the step of forming the second shield layer. The method further includes the step of forming the conductive layer so that at least part of the conductive layer is placed in the groove, being insulated from the shield layer having the groove or the shield layers facing the groove.
In the first method of manufacturing a thin-film magnetic head of the invention, the at least part of the conductive layer connected to the magnetoresistive element is placed in the groove formed in either the first shield layer or the second shield layer, or between the first and second shield layers, being insulated from the shield layer having the groove or the shield layers facing the groove. As a result, the insulation property is improved between the conductive layer and the shield layer without increasing the thickness of the insulating layer between the magnetoresistive element and the shield layer.
In the first method, the groove may be formed in the first shield layer. In this case the following configurations (1) to (5) are possible. (1) The at least part of the conductive layer placed in the groove is formed at the same time as the first shield layer and made of the same material as the first shield layer in the step of forming the first shield layer and the step of forming the conductive layer. (2) The method further comprises the step of forming a seed layer electrically connected to the first shield layer, formed in a region greater than a region where the first shield layer is formed, and used for forming the first shield layer. (3) The first shield layer is divided into a portion facing the magnetoresistive element and a portion not facing the magnetoresistive element. (4) The first shield layer is formed by plating. (5) The at least part of the conductive layer is formed by plating.
As stated above, if the at least part of the conductive layer placed in the groove is formed at the same time as the first shield layer and made of the same material as the first shield layer in the step of forming the first shield layer and the step of forming the conductive layer, the first shield layer and the at least part of the conductive layer may be formed by plating or formed by depositing films through sputtering and selectively etching the films through dry etching.
The first method may further include the step of forming an insulating film placed in the groove. The insulating film insulates the at least part of the conductive layer from the shield layer having the groove or the shield layers facing the groove.
The first method may further include the step of forming an induction-type magnetic transducer having two magnetic layers magnetically coupled to each other and a thin-film coil placed between the two magnetic layers. Parts of sides of the two magnetic layers facing a recording medium include magnetic pole portions opposed to each other with a gap layer in between. The magnetic layers are each made up of at least one layer. In this case the following configurations (1) to (4) are possible. (1) One of the first and second shield layers functions as one of the two magnetic layers as well. (2) At least part of the groove is placed around a region facing the two magnetic layers and the thin-film coil of the induction-type magnetic transducer. (3) At least part of the groove is placed to pass through a region facing the two magnetic layers and the thin-film coil of the induction-type magnetic transducer. (4) The method further includes the step of forming a shield layer for shielding at least part of the conductive layer at the same time as forming the one of the magnetic layers of the induction-type magnetic transducer.
The first method may further include the step of forming a shield layer for shielding at least part of the conductive layer.
In the first method, for example, a first portion and a second portion of the second shield layer are formed in the step of forming the second shield layer, at least part of the first portion being placed in the same plane as the first shield layer so that the groove is formed between the first shield layer and the first portion, the second portion being connected to the first portion and being opposed to the first shield layer with the magnetoresistive element in between. In this case the following configurations (1) to (4) are possible. (1) The first portion of the second shield layer is formed at the same time as the first shield layer and made of the same material as the first shield layer in the step of forming the first shield layer and the step of forming the second shield layer. (2) The method further includes the step of forming an induction-type magnetic transducer having two magnetic layers magnetically coupled to each other and a thin-film coil placed between the two magnetic layers. Parts of sides of the two magnetic layers facing a recording medium include magnetic pole portions opposed to each other with a gap layer in between. The magnetic layers are each made up of at least one layer. (3) The first shield layer and the first portion of the second shield layer placed in the one plane are formed by plating. (4) The at least part of the conductive layer is formed by plating.
If the method includes the step of forming the induction-type magnetic transducer as stated above, at least part of the thin-film coil may be placed on a side of the second portion of the second shield layer in a direction parallel to surfaces of the second portion.
If the method includes the step of forming the induction-type magnetic transducer as stated above, the at least part of the conductive layer and at least part of the thin-film coil may be formed by plating, for example, at the same time in the step of forming the conductive layer and the step of forming the induction-type magnetic transducer.
If the method includes the step of forming the induction-type magnetic transducer as stated above, the thin-film magnetic head may further comprise a base body having a concave portion. At least part of the first shield layer is placed in a portion other than the concave portion on the surface of the base body where the concave portion is formed. Part of the first portion of the second shield layer is placed in a portion other than the concave portion on the surface of the base body where the concave portion is formed. The remaining part of the first portion of the second shield layer is placed along the inner surface of the concave portion. At least part of the thin-film coil is placed in the concave portion. In this case the following configurations (1) and (2) are possible. (1) The step of forming the induction-type magnetic transducer includes the steps of: forming the at least part of the thin-film coil in the concave portion; forming an insulating portion to cover the at least part of the thin-film coil in the concave portion; and flattening the surfaces of the insulating portion, the first shield layer and the first portion of the second shield layer so that the surfaces are brought to one plane. (2) The step of forming the induction-type magnetic transducer includes the steps of: forming part of the thin-film coil in the concave portion; forming a first insulating portion to cover the part of the thin-film coil in the concave portion; flattening the surfaces of the first insulating portion, the first shield layer and the first portion of the second shield layer so that the surfaces are brought to one plane; forming the remaining part of the thin-film coil on the first insulating portion; forming a second insulating portion to cover the remaining part of the thin-film coil; and flattening the surfaces of the second insulating portion and the second portion of the second shield layer so that the surfaces are brought to one plane.
A second or third method of the invention is provided for manufacturing a thin-film magnetic head comprising: a magnetoresistive element; a first shield layer and a second shield layer for shielding the magnetoresistive element, wherein portions of the first shield layer and the second shield layer facing a recording medium are opposed to each other with the magnetoresistive element in between; a first insulating layer provided between the magnetoresistive element and the first shield layer and a second insulating layer provided between the magnetoresistive element and the second shield layer; and a conductive layer connected to the magnetoresistive element.
The second method of the invention includes the steps of: forming the first shield layer; forming the first insulating film on the first shield layer; forming the magnetoresistive element on the first insulating film; forming the second insulating film on the magnetoresistive element and the first insulating film; and forming the second shield layer so that the portion of the second shield layer facing the recording medium is opposed to the first shield layer with the first insulating layer, the magnetoresistive element and the second insulating layer in between. The first shield layer and at least part of the conductive layer are made of one material, placed in one plane and insulated from each other in the step of forming the first shield layer and the step of forming the conductive layer. The method further includes the step of forming a shield layer for shielding at least part of the conductive layer.
The third method of the invention includes the steps of: forming the first shield layer; forming the first insulating layer on the first shield layer; forming the magnetoresistive element on the first insulating layer; forming the second insulating layer on the magnetoresistive element and the first insulating layer; and forming the second shield layer so that the portion of the second shield layer facing the recording medium is opposed to the first shield layer with the first insulating layer, the magnetoresistive element and the second insulating layer in between. The first shield layer and at least part of the conductive layer are made of one material, placed in one plane and insulated from each other in the step of forming the first shield layer and the step of forming the conductive layer. The method further includes the step of forming a seed layer electrically connected to at least part of the conductive layer and used for forming the at least part of the conductive layer, the seed layer being formed in a region greater than a region where the at least part of the conductive layer is formed.
In the second or third method of the invention, the first shield layer and at least part of the conductive layer are made of one material, placed in one plane and insulated from each other. As a result, the insulation property is improved between the conductive layer and the shield layer without increasing the thickness of the insulating layer between the magnetoresistive element and the shield layer.
The third method may further include the step of forming a shield layer for shielding the at least part of the conductive layer.
A thin-film magnetic head material of the invention is used for manufacturing a thin-film magnetic head comprising: a magnetoresistive element; a first shield layer and a second shield layer for shielding the magnetoresistive element, wherein portions of the first shield layer and the second shield layer facing a recording medium are opposed to each other with the magnetoresistive element in between; a first insulating layer provided between the magnetoresistive element and the first shield layer and a second insulating layer provided between the magnetoresistive element and the second shield layer; a conductive layer connected to the magnetoresistive element; and an induction-type magnetic transducer. In the magnetic head the induction-type magnetic transducer has a first magnetic layer and a second magnetic layer magnetically coupled to each other and a thin-film coil placed between the two magnetic layers. Parts of sides of the two magnetic layers facing a recording medium include magnetic pole portions opposed to each other with a gap layer in between. The magnetic layers are each made up of at least one layer. The second shield layer includes a first portion at least part of which is placed in the same plane as the first shield layer and a second portion connected to the first portion, the second portion being opposed to the first shield layer with the magnetoresistive element in between. The second shield layer functions as the first magnetic layer as well.
The thin-film magnetic head material of the invention comprises: the first shield layer; the first portion of the second shield layer placed such that a groove in which at least part of the conductive layer is placed is formed between the first shield layer and the first portion; the at least part of the conductive layer placed in the groove, being insulated from the first shield layer and the first portion of the second shield layer; and at least part of the thin-film coil placed to face the first portion of the second shield layer.
In the thin-film magnetic head material of the invention, at least part of the conductive layer connected to the magnetoresistive element is placed in the groove formed between the first layer and the first portion of the second shield layer, being insulated from the first shield layer and the first portion. As a result, the insulation property is improved between the conductive layer and the shield layer without increasing the thickness of the insulating layer between the magnetoresistive element and the shield layer.
The thin-film magnetic head material of the invention may further comprise an insulating film placed in the groove. The insulating film insulates at least part of the conductive layer from the first shield layer and the first portion of the second shield layer.
The thin-film magnetic head material of the invention may further comprise a base body having a concave potion. At least part of the first shield layer is placed in a portion other than the concave portion on the surface of the base body where the concave portion is formed. Part of the first portion of the second shield layer is placed in a portion other than the concave portion on the surface of the base body where the concave portion is formed. The remaining part of the first portion of the second shield layer is placed along the inner surface of the concave portion. At least part of the thin-film coil is placed in the concave portion.
A method of the invention is provided for manufacturing a thin-film magnetic head material used for manufacturing a thin-film magnetic head comprising: a magnetoresistive element; a first shield layer and a second shield layer for shielding the magnetoresistive element, wherein portions of the first shield layer and the second shield layer facing a recording medium are opposed to each other with the magnetoresistive element in between; a first insulating layer provided between the magnetoresistive element and the first shield layer and a second insulating layer provided between the magnetoresistive element and the second shield layer; a conductive layer connected to the magnetoresistive element; and an induction-type magnetic transducer. In the magnetic head, the induction-type magnetic transducer has a first magnetic layer and a second magnetic layer magnetically coupled to each other and a thin-film coil placed between the two magnetic layers. Parts of sides of the two magnetic layers facing a recording medium include magnetic pole portions opposed to each other with a gap layer in between. The magnetic layers are each made up of at least one layer. The second shield layer includes a first portion at least part of which is placed in the same plane as the first shield layer and a second portion connected to the first portion, the second portion being opposed to the first shield layer with the magnetoresistive element in between. The second shield layer functions as the first magnetic layer as well.
The method of manufacturing a thin-film magnetic head material of the invention includes the steps of: forming the first shield layer; forming the first portion of the second shield layer such that a groove in which at least part of the conductive layer is placed is formed between the first shield layer and the first portion; forming the at least part of the conductive layer placed in the groove, being insulated from the first shield layer and the first portion of the second shield layer; and forming at least part of the thin-film coil on the first portion of the second shield layer.
In the method of manufacturing a thin-film magnetic head material of the invention, at least part of the conductive layer connected to the magnetoresistive element is placed in the groove formed between the first layer and the first portion of the second shield layer, being insulated from the first shield layer and the first portion. As a result, the insulation property is improved between the conductive layer and the shield layer without increasing the thickness of the insulating layer between the magnetoresistive element and the shield layer.
The method may further include the step of forming an insulating film placed in the groove, the insulating film insulating at least part of the conductive layer from the first shield layer and the first portion of the second shield layer.
In the method the first portion of the second shield layer may be formed at the same time as the first shield layer and made of the same material as the first shield layer in the step of forming the first shield layer and the step of forming the first portion of the second shield layer.
In the method the first shield layer and the first portion of the second shield layer may be formed by plating. At least part of the conductive layer may be formed by plating.
In the method the at least part of the conductive layer and the at least part of the thin-film coil may be formed by plating at the same time in the step of forming the at least part of the conductive layer and the step of forming the at least part of the thin-film coil.
In the method the thin-film magnetic head material may comprise a base body having a concave portion. At least part of the first shield layer is placed in a portion other than the concave portion on the surface of the base body where the concave portion is formed. Part of the first portion of the second shield layer is placed in a portion other than the concave portion on the surface of the base body where the concave portion is formed. The remaining part of the first portion of the second shield layer is placed along the inner surface of the concave portion. At least part of the thin-film coil is placed in the concave portion.
The method may further include the steps of: forming an insulating portion to cover the at least part of the thin-film coil in the concave portion; and flattening the surfaces of the insulating portion, the first shield layer and the first portion of the second shield layer so that the surfaces are brought to one plane.
Other and further objects, features and advantages of the invention will appear more fully from the following description.